1. Field of the Invention
This invention relates to an image shake correction device for correcting the image shake on the image focal plane of an optical apparatus due to vibration of an optical apparatus such as a camera, and an optical apparatus provided with the image shake correction device.
2. Description of the Prior Art
Heretofore, in the camera industry field, a correction optical system which drives a correction lens, which is located behind the photographic lens, eccentrically in a plane perpendicular to the optical axis has been known as a means for correcting the image shake on the image forming plane due to camera vibration caused during photographic activity. In the lens device provided with a correction optical system, an actuator used exclusively for driving the correction lens in a predetermined direction is incorporated, the movement of a camera is detected by means of a camera shake sensor such as an angular acceleration sensor, and the correction lens is driven based on the detected signal.
The piezoelectric actuator has been proposed which utilizes a phenomenon that a driven member coupled frictionally with a driving shaft moves in a predetermined direction with repeated reciprocal vibration when the driving shaft is vibrated reciprocally in different speed by a piezoelectric transducer which is serves as the actuator for driving such a correction optical system. This structure can drive eccentrically the correction lens having a holder frame coupled with the driven member of the piezoelectric actuator in a plane perpendicular to the optical axis (refer to Japanese Laid Open Patent No. Hei 8-43872 as an example).
Also, the prior art recognises a moving coil type of actuator which has two electromagnetic coils in a plane perpendicular to the optical axis provided on a holder frame of a correction lens and has a yoke and a permanent magnet located correspondingly to the two electromagnetic coils provided on a fixed frame of a lens barrel.
The above-mentioned piezoelectric actuator and moving coil type actuator are suitable for the correction lens driving mechanism for correcting image shake because of excellent controllability, however, these driving mechanisms are large and heavy to result in a large-sized and expensive optical apparatus as a whole, therefore a compact and light-weight correction lens driving mechanism has been desired to be realized.